/*
 * Copyright 2012-2025 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.boot.testsupport.classpath.resources;

import java.io.IOException;
import java.io.UncheckedIOException;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;

/**
 * A {@link ClassLoader} that provides access to {@link Resources resources}.
 *
 * @author Andy Wilkinson
 */
class ResourcesClassLoader extends ClassLoader {

	private final Resources resources;

	ResourcesClassLoader(ClassLoader parent, Resources resources) {
		super(parent);
		this.resources = resources;
	}

	@Override
	protected URL findResource(String name) {
		Path resource = this.resources.getRoot().resolve(name);
		if (Files.exists(resource)) {
			try {
				return resource.toUri().toURL();
			}
			catch (IOException ex) {
				throw new UncheckedIOException(ex);
			}
		}
		return null;
	}

	@Override
	protected Enumeration<URL> findResources(String name) throws IOException {
		URL resourceUrl = findResource(name);
		return (resourceUrl != null) ? Collections.enumeration(List.of(resourceUrl)) : Collections.emptyEnumeration();
	}

}
